We shall be working in three related areas in the coming year. We shall refine our measurements of intracellular and surface bound cations in chick embryo fibroblasts and 3T3 cells in different states of growth and metabolism. We shall measure various physical and biological parameters of the insoluble complexes of calcium and inorganic phosphates which stimulate growth and metabolism in 3T3 cells. And we shall determine the metabolic requirements for 3T3 cell survival as well as growth, as the two are closely related and controlled by the same external and probably internal signals.